xref: /freebsd/bin/sh/jobs.c (revision f44ac8cc9c10d7305223a10b8dbd8e234388cc73)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Kenneth Almquist.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/ioctl.h>
34 #include <sys/param.h>
35 #include <sys/resource.h>
36 #include <sys/time.h>
37 #include <sys/wait.h>
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <paths.h>
41 #include <signal.h>
42 #include <stddef.h>
43 #include <stdlib.h>
44 #include <unistd.h>
45 
46 #include "shell.h"
47 #if JOBS
48 #include <termios.h>
49 #undef CEOF			/* syntax.h redefines this */
50 #endif
51 #include "redir.h"
52 #include "exec.h"
53 #include "show.h"
54 #include "main.h"
55 #include "parser.h"
56 #include "nodes.h"
57 #include "jobs.h"
58 #include "options.h"
59 #include "trap.h"
60 #include "syntax.h"
61 #include "input.h"
62 #include "output.h"
63 #include "memalloc.h"
64 #include "error.h"
65 #include "mystring.h"
66 #include "var.h"
67 #include "builtins.h"
68 #include "eval.h"
69 
70 
71 /*
72  * A job structure contains information about a job.  A job is either a
73  * single process or a set of processes contained in a pipeline.  In the
74  * latter case, pidlist will be non-NULL, and will point to a -1 terminated
75  * array of pids.
76  */
77 
78 struct procstat {
79 	pid_t pid;		/* process id */
80 	int status;		/* status flags (defined above) */
81 	char *cmd;		/* text of command being run */
82 };
83 
84 
85 /* states */
86 #define JOBSTOPPED 1		/* all procs are stopped */
87 #define JOBDONE 2		/* all procs are completed */
88 
89 
90 struct job {
91 	struct procstat ps0;	/* status of process */
92 	struct procstat *ps;	/* status or processes when more than one */
93 	short nprocs;		/* number of processes */
94 	pid_t pgrp;		/* process group of this job */
95 	char state;		/* true if job is finished */
96 	char used;		/* true if this entry is in use */
97 	char changed;		/* true if status has changed */
98 	char foreground;	/* true if running in the foreground */
99 	char remembered;	/* true if $! referenced */
100 	char pipefail;		/* pass any non-zero status */
101 #if JOBS
102 	char jobctl;		/* job running under job control */
103 	struct job *next;	/* job used after this one */
104 #endif
105 };
106 
107 
108 static struct job *jobtab;	/* array of jobs */
109 static int njobs;		/* size of array */
110 static pid_t backgndpid = -1;	/* pid of last background process */
111 static struct job *bgjob = NULL; /* last background process */
112 #if JOBS
113 static struct job *jobmru;	/* most recently used job list */
114 static pid_t initialpgrp;	/* pgrp of shell on invocation */
115 #endif
116 static int ttyfd = -1;
117 
118 /* mode flags for dowait */
119 #define DOWAIT_BLOCK	0x1 /* wait until a child exits */
120 #define DOWAIT_SIG	0x2 /* if DOWAIT_BLOCK, abort on signal */
121 #define DOWAIT_SIG_TRAP	0x4 /* if DOWAIT_SIG, abort on trapped signal only */
122 
123 #if JOBS
124 static void restartjob(struct job *);
125 #endif
126 static void freejob(struct job *);
127 static int waitcmdloop(struct job *);
128 static struct job *getjob_nonotfound(const char *);
129 static struct job *getjob(const char *);
130 pid_t killjob(const char *, int);
131 static pid_t dowait(int, struct job *);
132 static void checkzombies(void);
133 static void cmdtxt(union node *);
134 static void cmdputs(const char *);
135 #if JOBS
136 static void setcurjob(struct job *);
137 static void deljob(struct job *);
138 static struct job *getcurjob(struct job *);
139 #endif
140 static int getjobstatus(const struct job *);
141 static void printjobcmd(struct job *);
142 static void showjob(struct job *, int);
143 
144 
145 /*
146  * Turn job control on and off.
147  */
148 
149 static int jobctl;
150 
151 #if JOBS
152 static void
jobctl_notty(void)153 jobctl_notty(void)
154 {
155 	if (ttyfd >= 0) {
156 		close(ttyfd);
157 		ttyfd = -1;
158 	}
159 	if (!iflag) {
160 		setsignal(SIGTSTP);
161 		setsignal(SIGTTOU);
162 		setsignal(SIGTTIN);
163 		jobctl = 1;
164 		return;
165 	}
166 	out2fmt_flush("sh: can't access tty; job control turned off\n");
167 	mflag = 0;
168 }
169 
170 void
setjobctl(int on)171 setjobctl(int on)
172 {
173 	int i;
174 
175 	if (on == jobctl || rootshell == 0)
176 		return;
177 	if (on) {
178 		if (ttyfd != -1)
179 			close(ttyfd);
180 		if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) {
181 			i = 0;
182 			while (i <= 2 && !isatty(i))
183 				i++;
184 			if (i > 2 ||
185 			    (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) {
186 				jobctl_notty();
187 				return;
188 			}
189 		}
190 		if (ttyfd < 10) {
191 			/*
192 			 * Keep our TTY file descriptor out of the way of
193 			 * the user's redirections.
194 			 */
195 			if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) {
196 				jobctl_notty();
197 				return;
198 			}
199 			close(ttyfd);
200 			ttyfd = i;
201 		}
202 		do { /* while we are in the background */
203 			initialpgrp = tcgetpgrp(ttyfd);
204 			if (initialpgrp < 0) {
205 				jobctl_notty();
206 				return;
207 			}
208 			if (initialpgrp != getpgrp()) {
209 				if (!iflag) {
210 					initialpgrp = -1;
211 					jobctl_notty();
212 					return;
213 				}
214 				kill(0, SIGTTIN);
215 				continue;
216 			}
217 		} while (0);
218 		setsignal(SIGTSTP);
219 		setsignal(SIGTTOU);
220 		setsignal(SIGTTIN);
221 		setpgid(0, rootpid);
222 		tcsetpgrp(ttyfd, rootpid);
223 	} else { /* turning job control off */
224 		setpgid(0, initialpgrp);
225 		if (ttyfd >= 0) {
226 			tcsetpgrp(ttyfd, initialpgrp);
227 			close(ttyfd);
228 			ttyfd = -1;
229 		}
230 		setsignal(SIGTSTP);
231 		setsignal(SIGTTOU);
232 		setsignal(SIGTTIN);
233 	}
234 	jobctl = on;
235 }
236 #endif
237 
238 
239 #if JOBS
240 int
fgcmd(int argc __unused,char ** argv __unused)241 fgcmd(int argc __unused, char **argv __unused)
242 {
243 	struct job *jp;
244 	pid_t pgrp;
245 	int status;
246 
247 	nextopt("");
248 	jp = getjob(*argptr);
249 	if (jp->jobctl == 0)
250 		error("job not created under job control");
251 	printjobcmd(jp);
252 	flushout(&output);
253 	pgrp = jp->ps[0].pid;
254 	if (ttyfd >= 0)
255 		tcsetpgrp(ttyfd, pgrp);
256 	restartjob(jp);
257 	jp->foreground = 1;
258 	INTOFF;
259 	status = waitforjob(jp, (int *)NULL);
260 	INTON;
261 	return status;
262 }
263 
264 
265 int
bgcmd(int argc __unused,char ** argv __unused)266 bgcmd(int argc __unused, char **argv __unused)
267 {
268 	struct job *jp;
269 
270 	nextopt("");
271 	do {
272 		jp = getjob(*argptr);
273 		if (jp->jobctl == 0)
274 			error("job not created under job control");
275 		if (jp->state == JOBDONE)
276 			continue;
277 		restartjob(jp);
278 		jp->foreground = 0;
279 		out1fmt("[%td] ", jp - jobtab + 1);
280 		printjobcmd(jp);
281 	} while (*argptr != NULL && *++argptr != NULL);
282 	return 0;
283 }
284 
285 
286 static void
restartjob(struct job * jp)287 restartjob(struct job *jp)
288 {
289 	struct procstat *ps;
290 	int i;
291 
292 	if (jp->state == JOBDONE)
293 		return;
294 	setcurjob(jp);
295 	INTOFF;
296 	kill(-jp->ps[0].pid, SIGCONT);
297 	for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
298 		if (WIFSTOPPED(ps->status)) {
299 			ps->status = -1;
300 			jp->state = 0;
301 		}
302 	}
303 	INTON;
304 }
305 #endif
306 
307 
308 int
jobscmd(int argc __unused,char * argv[]__unused)309 jobscmd(int argc __unused, char *argv[] __unused)
310 {
311 	char *id;
312 	int ch, mode;
313 
314 	mode = SHOWJOBS_DEFAULT;
315 	while ((ch = nextopt("lps")) != '\0') {
316 		switch (ch) {
317 		case 'l':
318 			mode = SHOWJOBS_VERBOSE;
319 			break;
320 		case 'p':
321 			mode = SHOWJOBS_PGIDS;
322 			break;
323 		case 's':
324 			mode = SHOWJOBS_PIDS;
325 			break;
326 		}
327 	}
328 
329 	if (*argptr == NULL)
330 		showjobs(0, mode);
331 	else
332 		while ((id = *argptr++) != NULL)
333 			showjob(getjob(id), mode);
334 
335 	return (0);
336 }
337 
getjobstatus(const struct job * jp)338 static int getjobstatus(const struct job *jp)
339 {
340 	int i, status;
341 
342 	if (!jp->pipefail)
343 		return (jp->ps[jp->nprocs - 1].status);
344 	for (i = jp->nprocs - 1; i >= 0; i--) {
345 		status = jp->ps[i].status;
346 		if (status != 0)
347 			return (status);
348 	}
349 	return (0);
350 }
351 
352 static void
printjobcmd(struct job * jp)353 printjobcmd(struct job *jp)
354 {
355 	struct procstat *ps;
356 	int i;
357 
358 	for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
359 		out1str(ps->cmd);
360 		if (i > 0)
361 			out1str(" | ");
362 	}
363 	out1c('\n');
364 }
365 
366 static void
showjob(struct job * jp,int mode)367 showjob(struct job *jp, int mode)
368 {
369 	char s[64];
370 	char statebuf[16];
371 	const char *statestr, *coredump;
372 	struct procstat *ps;
373 	struct job *j;
374 	int col, curr, i, jobno, prev, procno, status;
375 	char c;
376 
377 	procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs;
378 	jobno = jp - jobtab + 1;
379 	curr = prev = 0;
380 #if JOBS
381 	if ((j = getcurjob(NULL)) != NULL) {
382 		curr = j - jobtab + 1;
383 		if ((j = getcurjob(j)) != NULL)
384 			prev = j - jobtab + 1;
385 	}
386 #endif
387 	coredump = "";
388 	status = getjobstatus(jp);
389 	if (jp->state == 0) {
390 		statestr = "Running";
391 #if JOBS
392 	} else if (jp->state == JOBSTOPPED) {
393 		ps = jp->ps + jp->nprocs - 1;
394 		while (!WIFSTOPPED(ps->status) && ps > jp->ps)
395 			ps--;
396 		if (WIFSTOPPED(ps->status))
397 			i = WSTOPSIG(ps->status);
398 		else
399 			i = -1;
400 		statestr = strsignal(i);
401 		if (statestr == NULL)
402 			statestr = "Suspended";
403 #endif
404 	} else if (WIFEXITED(status)) {
405 		if (WEXITSTATUS(status) == 0)
406 			statestr = "Done";
407 		else {
408 			fmtstr(statebuf, sizeof(statebuf), "Done(%d)",
409 			    WEXITSTATUS(status));
410 			statestr = statebuf;
411 		}
412 	} else {
413 		i = WTERMSIG(status);
414 		statestr = strsignal(i);
415 		if (statestr == NULL)
416 			statestr = "Unknown signal";
417 		if (WCOREDUMP(status))
418 			coredump = " (core dumped)";
419 	}
420 
421 	for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */
422 		if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) {
423 			out1fmt("%d\n", (int)ps->pid);
424 			continue;
425 		}
426 		if (mode != SHOWJOBS_VERBOSE && ps != jp->ps)
427 			continue;
428 		if (jobno == curr && ps == jp->ps)
429 			c = '+';
430 		else if (jobno == prev && ps == jp->ps)
431 			c = '-';
432 		else
433 			c = ' ';
434 		if (ps == jp->ps)
435 			fmtstr(s, 64, "[%d] %c ", jobno, c);
436 		else
437 			fmtstr(s, 64, "    %c ", c);
438 		out1str(s);
439 		col = strlen(s);
440 		if (mode == SHOWJOBS_VERBOSE) {
441 			fmtstr(s, 64, "%d ", (int)ps->pid);
442 			out1str(s);
443 			col += strlen(s);
444 		}
445 		if (ps == jp->ps) {
446 			out1str(statestr);
447 			out1str(coredump);
448 			col += strlen(statestr) + strlen(coredump);
449 		}
450 		do {
451 			out1c(' ');
452 			col++;
453 		} while (col < 30);
454 		if (mode == SHOWJOBS_VERBOSE) {
455 			out1str(ps->cmd);
456 			out1c('\n');
457 		} else
458 			printjobcmd(jp);
459 	}
460 }
461 
462 /*
463  * Print a list of jobs.  If "change" is nonzero, only print jobs whose
464  * statuses have changed since the last call to showjobs.
465  *
466  * If the shell is interrupted in the process of creating a job, the
467  * result may be a job structure containing zero processes.  Such structures
468  * will be freed here.
469  */
470 
471 void
showjobs(int change,int mode)472 showjobs(int change, int mode)
473 {
474 	int jobno;
475 	struct job *jp;
476 
477 	TRACE(("showjobs(%d) called\n", change));
478 	checkzombies();
479 	for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
480 		if (! jp->used)
481 			continue;
482 		if (jp->nprocs == 0) {
483 			freejob(jp);
484 			continue;
485 		}
486 		if (change && ! jp->changed)
487 			continue;
488 		showjob(jp, mode);
489 		if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) {
490 			jp->changed = 0;
491 			/* Hack: discard jobs for which $! has not been
492 			 * referenced in interactive mode when they terminate.
493 			 */
494 			if (jp->state == JOBDONE && !jp->remembered &&
495 					(iflag || jp != bgjob)) {
496 				freejob(jp);
497 			}
498 		}
499 	}
500 }
501 
502 
503 /*
504  * Mark a job structure as unused.
505  */
506 
507 static void
freejob(struct job * jp)508 freejob(struct job *jp)
509 {
510 	struct procstat *ps;
511 	int i;
512 
513 	INTOFF;
514 	if (bgjob == jp)
515 		bgjob = NULL;
516 	for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
517 		if (ps->cmd != nullstr)
518 			ckfree(ps->cmd);
519 	}
520 	if (jp->ps != &jp->ps0)
521 		ckfree(jp->ps);
522 	jp->used = 0;
523 #if JOBS
524 	deljob(jp);
525 #endif
526 	INTON;
527 }
528 
529 
530 
531 int
waitcmd(int argc __unused,char ** argv __unused)532 waitcmd(int argc __unused, char **argv __unused)
533 {
534 	struct job *job;
535 	int retval;
536 
537 	nextopt("");
538 	if (*argptr == NULL)
539 		return (waitcmdloop(NULL));
540 
541 	do {
542 		job = getjob_nonotfound(*argptr);
543 		if (job == NULL)
544 			retval = 127;
545 		else
546 			retval = waitcmdloop(job);
547 		argptr++;
548 	} while (*argptr != NULL);
549 
550 	return (retval);
551 }
552 
553 static int
waitcmdloop(struct job * job)554 waitcmdloop(struct job *job)
555 {
556 	int status, retval, sig;
557 	struct job *jp;
558 
559 	/*
560 	 * Loop until a process is terminated or stopped, or a SIGINT is
561 	 * received.
562 	 */
563 
564 	do {
565 		if (job != NULL) {
566 			if (job->state == JOBDONE) {
567 				status = getjobstatus(job);
568 				if (WIFEXITED(status))
569 					retval = WEXITSTATUS(status);
570 				else
571 					retval = WTERMSIG(status) + 128;
572 				if (! iflag || ! job->changed)
573 					freejob(job);
574 				else {
575 					job->remembered = 0;
576 					deljob(job);
577 					if (job == bgjob)
578 						bgjob = NULL;
579 				}
580 				return retval;
581 			}
582 		} else {
583 			if (njobs == 0)
584 				return 0;
585 			for (jp = jobtab ; jp < jobtab + njobs; jp++)
586 				if (jp->used && jp->state == JOBDONE) {
587 					if (! iflag || ! jp->changed)
588 						freejob(jp);
589 					else {
590 						jp->remembered = 0;
591 						if (jp == bgjob)
592 							bgjob = NULL;
593 					}
594 				}
595 			for (jp = jobtab ; ; jp++) {
596 				if (jp >= jobtab + njobs) {	/* no running procs */
597 					return 0;
598 				}
599 				if (jp->used && jp->state == 0)
600 					break;
601 			}
602 		}
603 	} while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, job) != -1);
604 
605 	sig = pendingsig_waitcmd;
606 	pendingsig_waitcmd = 0;
607 	return sig + 128;
608 }
609 
610 
611 
612 int
jobidcmd(int argc __unused,char ** argv __unused)613 jobidcmd(int argc __unused, char **argv __unused)
614 {
615 	struct job *jp;
616 	int i;
617 
618 	nextopt("");
619 	jp = getjob(*argptr);
620 	for (i = 0 ; i < jp->nprocs ; ) {
621 		out1fmt("%d", (int)jp->ps[i].pid);
622 		out1c(++i < jp->nprocs? ' ' : '\n');
623 	}
624 	return 0;
625 }
626 
627 
628 
629 /*
630  * Convert a job name to a job structure.
631  */
632 
633 static struct job *
getjob_nonotfound(const char * name)634 getjob_nonotfound(const char *name)
635 {
636 	int jobno;
637 	struct job *found, *jp;
638 	size_t namelen;
639 	pid_t pid;
640 	int i;
641 
642 	if (name == NULL) {
643 #if JOBS
644 		name = "%+";
645 #else
646 		error("No current job");
647 #endif
648 	}
649 	if (name[0] == '%') {
650 		if (is_digit(name[1])) {
651 			jobno = number(name + 1);
652 			if (jobno > 0 && jobno <= njobs
653 			 && jobtab[jobno - 1].used != 0)
654 				return &jobtab[jobno - 1];
655 #if JOBS
656 		} else if ((name[1] == '%' || name[1] == '+') &&
657 		    name[2] == '\0') {
658 			if ((jp = getcurjob(NULL)) == NULL)
659 				error("No current job");
660 			return (jp);
661 		} else if (name[1] == '-' && name[2] == '\0') {
662 			if ((jp = getcurjob(NULL)) == NULL ||
663 			    (jp = getcurjob(jp)) == NULL)
664 				error("No previous job");
665 			return (jp);
666 #endif
667 		} else if (name[1] == '?') {
668 			found = NULL;
669 			for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
670 				if (jp->used && jp->nprocs > 0
671 				 && strstr(jp->ps[0].cmd, name + 2) != NULL) {
672 					if (found)
673 						error("%s: ambiguous", name);
674 					found = jp;
675 				}
676 			}
677 			if (found != NULL)
678 				return (found);
679 		} else {
680 			namelen = strlen(name);
681 			found = NULL;
682 			for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
683 				if (jp->used && jp->nprocs > 0
684 				 && strncmp(jp->ps[0].cmd, name + 1,
685 				 namelen - 1) == 0) {
686 					if (found)
687 						error("%s: ambiguous", name);
688 					found = jp;
689 				}
690 			}
691 			if (found)
692 				return found;
693 		}
694 	} else if (is_number(name)) {
695 		pid = (pid_t)number(name);
696 		for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
697 			if (jp->used && jp->nprocs > 0
698 			 && jp->ps[jp->nprocs - 1].pid == pid)
699 				return jp;
700 		}
701 	}
702 	return NULL;
703 }
704 
705 
706 static struct job *
getjob(const char * name)707 getjob(const char *name)
708 {
709 	struct job *jp;
710 
711 	jp = getjob_nonotfound(name);
712 	if (jp == NULL)
713 		error("No such job: %s", name);
714 	return (jp);
715 }
716 
717 
718 int
killjob(const char * name,int sig)719 killjob(const char *name, int sig)
720 {
721 	struct job *jp;
722 	int i, ret;
723 
724 	jp = getjob(name);
725 	if (jp->state == JOBDONE)
726 		return 0;
727 	if (jp->jobctl)
728 		return kill(-jp->ps[0].pid, sig);
729 	ret = -1;
730 	errno = ESRCH;
731 	for (i = 0; i < jp->nprocs; i++)
732 		if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) {
733 			if (kill(jp->ps[i].pid, sig) == 0)
734 				ret = 0;
735 		} else
736 			ret = 0;
737 	return ret;
738 }
739 
740 /*
741  * Return a new job structure,
742  */
743 
744 struct job *
makejob(union node * node __unused,int nprocs)745 makejob(union node *node __unused, int nprocs)
746 {
747 	int i;
748 	struct job *jp;
749 
750 	for (i = njobs, jp = jobtab ; ; jp++) {
751 		if (--i < 0) {
752 			INTOFF;
753 			if (njobs == 0) {
754 				jobtab = ckmalloc(4 * sizeof jobtab[0]);
755 #if JOBS
756 				jobmru = NULL;
757 #endif
758 			} else {
759 				jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
760 				memcpy(jp, jobtab, njobs * sizeof jp[0]);
761 #if JOBS
762 				/* Relocate `next' pointers and list head */
763 				if (jobmru != NULL)
764 					jobmru = &jp[jobmru - jobtab];
765 				for (i = 0; i < njobs; i++)
766 					if (jp[i].next != NULL)
767 						jp[i].next = &jp[jp[i].next -
768 						    jobtab];
769 #endif
770 				if (bgjob != NULL)
771 					bgjob = &jp[bgjob - jobtab];
772 				/* Relocate `ps' pointers */
773 				for (i = 0; i < njobs; i++)
774 					if (jp[i].ps == &jobtab[i].ps0)
775 						jp[i].ps = &jp[i].ps0;
776 				ckfree(jobtab);
777 				jobtab = jp;
778 			}
779 			jp = jobtab + njobs;
780 			for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0)
781 				;
782 			INTON;
783 			break;
784 		}
785 		if (jp->used == 0)
786 			break;
787 	}
788 	INTOFF;
789 	jp->state = 0;
790 	jp->used = 1;
791 	jp->changed = 0;
792 	jp->nprocs = 0;
793 	jp->foreground = 0;
794 	jp->remembered = 0;
795 	jp->pipefail = pipefailflag;
796 #if JOBS
797 	jp->jobctl = jobctl;
798 	jp->next = NULL;
799 #endif
800 	if (nprocs > 1) {
801 		jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
802 	} else {
803 		jp->ps = &jp->ps0;
804 	}
805 	INTON;
806 	TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs,
807 	    jp - jobtab + 1));
808 	return jp;
809 }
810 
811 #if JOBS
812 static void
setcurjob(struct job * cj)813 setcurjob(struct job *cj)
814 {
815 	struct job *jp, *prev;
816 
817 	for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
818 		if (jp == cj) {
819 			if (prev != NULL)
820 				prev->next = jp->next;
821 			else
822 				jobmru = jp->next;
823 			jp->next = jobmru;
824 			jobmru = cj;
825 			return;
826 		}
827 	}
828 	cj->next = jobmru;
829 	jobmru = cj;
830 }
831 
832 static void
deljob(struct job * j)833 deljob(struct job *j)
834 {
835 	struct job *jp, *prev;
836 
837 	for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
838 		if (jp == j) {
839 			if (prev != NULL)
840 				prev->next = jp->next;
841 			else
842 				jobmru = jp->next;
843 			return;
844 		}
845 	}
846 }
847 
848 /*
849  * Return the most recently used job that isn't `nj', and preferably one
850  * that is stopped.
851  */
852 static struct job *
getcurjob(struct job * nj)853 getcurjob(struct job *nj)
854 {
855 	struct job *jp;
856 
857 	/* Try to find a stopped one.. */
858 	for (jp = jobmru; jp != NULL; jp = jp->next)
859 		if (jp->used && jp != nj && jp->state == JOBSTOPPED)
860 			return (jp);
861 	/* Otherwise the most recently used job that isn't `nj' */
862 	for (jp = jobmru; jp != NULL; jp = jp->next)
863 		if (jp->used && jp != nj)
864 			return (jp);
865 
866 	return (NULL);
867 }
868 
869 #endif
870 
871 /*
872  * Fork of a subshell.  If we are doing job control, give the subshell its
873  * own process group.  Jp is a job structure that the job is to be added to.
874  * N is the command that will be evaluated by the child.  Both jp and n may
875  * be NULL.  The mode parameter can be one of the following:
876  *	FORK_FG - Fork off a foreground process.
877  *	FORK_BG - Fork off a background process.
878  *	FORK_NOJOB - Like FORK_FG, but don't give the process its own
879  *		     process group even if job control is on.
880  *
881  * When job control is turned off, background processes have their standard
882  * input redirected to /dev/null (except for the second and later processes
883  * in a pipeline).
884  */
885 
886 pid_t
forkshell(struct job * jp,union node * n,int mode)887 forkshell(struct job *jp, union node *n, int mode)
888 {
889 	pid_t pid;
890 	pid_t pgrp;
891 
892 	TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n,
893 	    mode));
894 	INTOFF;
895 	if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0))
896 		checkzombies();
897 	flushall();
898 	pid = fork();
899 	if (pid == -1) {
900 		TRACE(("Fork failed, errno=%d\n", errno));
901 		INTON;
902 		error("Cannot fork: %s", strerror(errno));
903 	}
904 	if (pid == 0) {
905 		struct job *p;
906 		int wasroot;
907 		int i;
908 
909 		TRACE(("Child shell %d\n", (int)getpid()));
910 		wasroot = rootshell;
911 		rootshell = 0;
912 		handler = &main_handler;
913 		closescript();
914 		INTON;
915 		forcelocal = 0;
916 		clear_traps();
917 #if JOBS
918 		jobctl = 0;		/* do job control only in root shell */
919 		if (wasroot && mode != FORK_NOJOB && mflag) {
920 			if (jp == NULL || jp->nprocs == 0)
921 				pgrp = getpid();
922 			else
923 				pgrp = jp->ps[0].pid;
924 			if (setpgid(0, pgrp) == 0 && mode == FORK_FG &&
925 			    ttyfd >= 0) {
926 				/*
927 				 * Each process in a pipeline must have the tty
928 				 * pgrp set before running its code.
929 				 * Only for pipelines of three or more processes
930 				 * could this be reduced to two calls.
931 				 */
932 				if (tcsetpgrp(ttyfd, pgrp) < 0)
933 					error("tcsetpgrp failed, errno=%d", errno);
934 			}
935 			setsignal(SIGTSTP);
936 			setsignal(SIGTTOU);
937 		} else if (mode == FORK_BG) {
938 			ignoresig(SIGINT);
939 			ignoresig(SIGQUIT);
940 			if ((jp == NULL || jp->nprocs == 0) &&
941 			    ! fd0_redirected_p ()) {
942 				close(0);
943 				if (open(_PATH_DEVNULL, O_RDONLY) != 0)
944 					error("cannot open %s: %s",
945 					    _PATH_DEVNULL, strerror(errno));
946 			}
947 		}
948 #else
949 		if (mode == FORK_BG) {
950 			ignoresig(SIGINT);
951 			ignoresig(SIGQUIT);
952 			if ((jp == NULL || jp->nprocs == 0) &&
953 			    ! fd0_redirected_p ()) {
954 				close(0);
955 				if (open(_PATH_DEVNULL, O_RDONLY) != 0)
956 					error("cannot open %s: %s",
957 					    _PATH_DEVNULL, strerror(errno));
958 			}
959 		}
960 #endif
961 		INTOFF;
962 		for (i = njobs, p = jobtab ; --i >= 0 ; p++)
963 			if (p->used)
964 				freejob(p);
965 		INTON;
966 		if (wasroot && iflag) {
967 			setsignal(SIGINT);
968 			setsignal(SIGQUIT);
969 			setsignal(SIGTERM);
970 		}
971 		return pid;
972 	}
973 	if (rootshell && mode != FORK_NOJOB && mflag) {
974 		if (jp == NULL || jp->nprocs == 0)
975 			pgrp = pid;
976 		else
977 			pgrp = jp->ps[0].pid;
978 		setpgid(pid, pgrp);
979 	}
980 	if (mode == FORK_BG) {
981 		if (bgjob != NULL && bgjob->state == JOBDONE &&
982 		    !bgjob->remembered && !iflag)
983 			freejob(bgjob);
984 		backgndpid = pid;		/* set $! */
985 		bgjob = jp;
986 	}
987 	if (jp) {
988 		struct procstat *ps = &jp->ps[jp->nprocs++];
989 		ps->pid = pid;
990 		ps->status = -1;
991 		ps->cmd = nullstr;
992 		if (iflag && rootshell && n)
993 			ps->cmd = commandtext(n);
994 		jp->foreground = mode == FORK_FG;
995 #if JOBS
996 		setcurjob(jp);
997 #endif
998 	}
999 	INTON;
1000 	TRACE(("In parent shell:  child = %d\n", (int)pid));
1001 	return pid;
1002 }
1003 
1004 
1005 pid_t
vforkexecshell(struct job * jp,char ** argv,char ** envp,const char * path,int idx,int pip[2])1006 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2])
1007 {
1008 	pid_t pid;
1009 	struct jmploc jmploc;
1010 	struct jmploc *savehandler;
1011 	int inton;
1012 
1013 	TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0],
1014 	    (void *)pip));
1015 	inton = is_int_on();
1016 	INTOFF;
1017 	flushall();
1018 	savehandler = handler;
1019 	pid = vfork();
1020 	if (pid == -1) {
1021 		TRACE(("Vfork failed, errno=%d\n", errno));
1022 		INTON;
1023 		error("Cannot fork: %s", strerror(errno));
1024 	}
1025 	if (pid == 0) {
1026 		TRACE(("Child shell %d\n", (int)getpid()));
1027 		if (setjmp(jmploc.loc))
1028 			_exit(exitstatus);
1029 		if (pip != NULL) {
1030 			close(pip[0]);
1031 			if (pip[1] != 1) {
1032 				dup2(pip[1], 1);
1033 				close(pip[1]);
1034 			}
1035 		}
1036 		handler = &jmploc;
1037 		shellexec(argv, envp, path, idx);
1038 	}
1039 	handler = savehandler;
1040 	if (jp) {
1041 		struct procstat *ps = &jp->ps[jp->nprocs++];
1042 		ps->pid = pid;
1043 		ps->status = -1;
1044 		ps->cmd = nullstr;
1045 		jp->foreground = 1;
1046 #if JOBS
1047 		setcurjob(jp);
1048 #endif
1049 	}
1050 	SETINTON(inton);
1051 	TRACE(("In parent shell:  child = %d\n", (int)pid));
1052 	return pid;
1053 }
1054 
1055 
1056 /*
1057  * Wait for job to finish.
1058  *
1059  * Under job control we have the problem that while a child process is
1060  * running interrupts generated by the user are sent to the child but not
1061  * to the shell.  This means that an infinite loop started by an inter-
1062  * active user may be hard to kill.  With job control turned off, an
1063  * interactive user may place an interactive program inside a loop.  If
1064  * the interactive program catches interrupts, the user doesn't want
1065  * these interrupts to also abort the loop.  The approach we take here
1066  * is to have the shell ignore interrupt signals while waiting for a
1067  * foreground process to terminate, and then send itself an interrupt
1068  * signal if the child process was terminated by an interrupt signal.
1069  * Unfortunately, some programs want to do a bit of cleanup and then
1070  * exit on interrupt; unless these processes terminate themselves by
1071  * sending a signal to themselves (instead of calling exit) they will
1072  * confuse this approach.
1073  */
1074 
1075 int
waitforjob(struct job * jp,int * signaled)1076 waitforjob(struct job *jp, int *signaled)
1077 {
1078 #if JOBS
1079 	int propagate_int = jp->jobctl && jp->foreground;
1080 #endif
1081 	int jobindex;
1082 	int status;
1083 	int st;
1084 
1085 	INTOFF;
1086 	TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1));
1087 	while (jp->state == 0)
1088 		if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG |
1089 		    DOWAIT_SIG_TRAP : 0), jp) == -1) {
1090 			jobindex = jp - jobtab;
1091 			dotrap();
1092 			jp = jobtab + jobindex;
1093 		}
1094 #if JOBS
1095 	if (jp->jobctl) {
1096 		if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0)
1097 			error("tcsetpgrp failed, errno=%d\n", errno);
1098 	}
1099 	if (jp->state == JOBSTOPPED)
1100 		setcurjob(jp);
1101 #endif
1102 	status = getjobstatus(jp);
1103 	if (signaled != NULL)
1104 		*signaled = WIFSIGNALED(status);
1105 	/* convert to 8 bits */
1106 	if (WIFEXITED(status))
1107 		st = WEXITSTATUS(status);
1108 #if JOBS
1109 	else if (WIFSTOPPED(status))
1110 		st = WSTOPSIG(status) + 128;
1111 #endif
1112 	else
1113 		st = WTERMSIG(status) + 128;
1114 	if (! JOBS || jp->state == JOBDONE)
1115 		freejob(jp);
1116 	if (int_pending()) {
1117 		if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT)
1118 			CLEAR_PENDING_INT;
1119 	}
1120 #if JOBS
1121 	else if (rootshell && propagate_int &&
1122 			WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
1123 		kill(getpid(), SIGINT);
1124 #endif
1125 	INTON;
1126 	return st;
1127 }
1128 
1129 
1130 static void
dummy_handler(int sig __unused)1131 dummy_handler(int sig __unused)
1132 {
1133 }
1134 
1135 /*
1136  * Wait for a process to terminate.
1137  */
1138 
1139 static pid_t
dowait(int mode,struct job * job)1140 dowait(int mode, struct job *job)
1141 {
1142 	struct sigaction sa, osa;
1143 	sigset_t mask, omask;
1144 	pid_t pid;
1145 	int status;
1146 	struct procstat *sp;
1147 	struct job *jp;
1148 	struct job *thisjob;
1149 	const char *sigstr;
1150 	int done;
1151 	int stopped;
1152 	int sig;
1153 	int coredump;
1154 	int wflags;
1155 	int restore_sigchld;
1156 
1157 	TRACE(("dowait(%d, %p) called\n", mode, job));
1158 	restore_sigchld = 0;
1159 	if ((mode & DOWAIT_SIG) != 0) {
1160 		sigfillset(&mask);
1161 		sigprocmask(SIG_BLOCK, &mask, &omask);
1162 		INTOFF;
1163 		if (!issigchldtrapped()) {
1164 			restore_sigchld = 1;
1165 			sa.sa_handler = dummy_handler;
1166 			sa.sa_flags = 0;
1167 			sigemptyset(&sa.sa_mask);
1168 			sigaction(SIGCHLD, &sa, &osa);
1169 		}
1170 	}
1171 	do {
1172 #if JOBS
1173 		if (iflag)
1174 			wflags = WUNTRACED | WCONTINUED;
1175 		else
1176 #endif
1177 			wflags = 0;
1178 		if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK)
1179 			wflags |= WNOHANG;
1180 		pid = wait3(&status, wflags, (struct rusage *)NULL);
1181 		TRACE(("wait returns %d, status=%d\n", (int)pid, status));
1182 		if (pid == 0 && (mode & DOWAIT_SIG) != 0) {
1183 			pid = -1;
1184 			if (((mode & DOWAIT_SIG_TRAP) != 0 ?
1185 			    pendingsig : pendingsig_waitcmd) != 0) {
1186 				errno = EINTR;
1187 				break;
1188 			}
1189 			sigsuspend(&omask);
1190 			if (int_pending())
1191 				break;
1192 		}
1193 	} while (pid == -1 && errno == EINTR);
1194 	if (pid == -1 && errno == ECHILD && job != NULL)
1195 		job->state = JOBDONE;
1196 	if ((mode & DOWAIT_SIG) != 0) {
1197 		if (restore_sigchld)
1198 			sigaction(SIGCHLD, &osa, NULL);
1199 		sigprocmask(SIG_SETMASK, &omask, NULL);
1200 		INTON;
1201 	}
1202 	if (pid <= 0)
1203 		return pid;
1204 	INTOFF;
1205 	thisjob = NULL;
1206 	for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
1207 		if (jp->used && jp->nprocs > 0) {
1208 			done = 1;
1209 			stopped = 1;
1210 			for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
1211 				if (sp->pid == -1)
1212 					continue;
1213 				if (sp->pid == pid && (sp->status == -1 ||
1214 				    WIFSTOPPED(sp->status))) {
1215 					TRACE(("Changing status of proc %d from 0x%x to 0x%x\n",
1216 						   (int)pid, sp->status,
1217 						   status));
1218 					if (WIFCONTINUED(status)) {
1219 						sp->status = -1;
1220 						jp->state = 0;
1221 					} else
1222 						sp->status = status;
1223 					thisjob = jp;
1224 				}
1225 				if (sp->status == -1)
1226 					stopped = 0;
1227 				else if (WIFSTOPPED(sp->status))
1228 					done = 0;
1229 			}
1230 			if (stopped) {		/* stopped or done */
1231 				int state = done? JOBDONE : JOBSTOPPED;
1232 				if (jp->state != state) {
1233 					TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
1234 					jp->state = state;
1235 					if (jp != job) {
1236 						if (done && !jp->remembered &&
1237 						    !iflag && jp != bgjob)
1238 							freejob(jp);
1239 #if JOBS
1240 						else if (done)
1241 							deljob(jp);
1242 #endif
1243 					}
1244 				}
1245 			}
1246 		}
1247 	}
1248 	INTON;
1249 	if (!thisjob || thisjob->state == 0)
1250 		;
1251 	else if ((!rootshell || !iflag || thisjob == job) &&
1252 	    thisjob->foreground && thisjob->state != JOBSTOPPED) {
1253 		sig = 0;
1254 		coredump = 0;
1255 		for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++)
1256 			if (WIFSIGNALED(sp->status)) {
1257 				sig = WTERMSIG(sp->status);
1258 				coredump = WCOREDUMP(sp->status);
1259 			}
1260 		if (sig > 0 && sig != SIGINT && sig != SIGPIPE) {
1261 			sigstr = strsignal(sig);
1262 			if (sigstr != NULL)
1263 				out2str(sigstr);
1264 			else
1265 				out2str("Unknown signal");
1266 			if (coredump)
1267 				out2str(" (core dumped)");
1268 			out2c('\n');
1269 			flushout(out2);
1270 		}
1271 	} else {
1272 		TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job));
1273 		thisjob->changed = 1;
1274 	}
1275 	return pid;
1276 }
1277 
1278 
1279 
1280 /*
1281  * return 1 if there are stopped jobs, otherwise 0
1282  */
1283 int job_warning = 0;
1284 int
stoppedjobs(void)1285 stoppedjobs(void)
1286 {
1287 	int jobno;
1288 	struct job *jp;
1289 
1290 	if (job_warning)
1291 		return (0);
1292 	for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
1293 		if (jp->used == 0)
1294 			continue;
1295 		if (jp->state == JOBSTOPPED) {
1296 			out2fmt_flush("You have stopped jobs.\n");
1297 			job_warning = 2;
1298 			return (1);
1299 		}
1300 	}
1301 
1302 	return (0);
1303 }
1304 
1305 
1306 static void
checkzombies(void)1307 checkzombies(void)
1308 {
1309 	while (njobs > 0 && dowait(0, NULL) > 0)
1310 		;
1311 }
1312 
1313 
1314 int
backgndpidset(void)1315 backgndpidset(void)
1316 {
1317 	return backgndpid != -1;
1318 }
1319 
1320 
1321 pid_t
backgndpidval(void)1322 backgndpidval(void)
1323 {
1324 	if (bgjob != NULL && !forcelocal)
1325 		bgjob->remembered = 1;
1326 	return backgndpid;
1327 }
1328 
1329 /*
1330  * Return a string identifying a command (to be printed by the
1331  * jobs command.
1332  */
1333 
1334 static char *cmdnextc;
1335 static int cmdnleft;
1336 #define MAXCMDTEXT	200
1337 
1338 char *
commandtext(union node * n)1339 commandtext(union node *n)
1340 {
1341 	char *name;
1342 
1343 	cmdnextc = name = ckmalloc(MAXCMDTEXT);
1344 	cmdnleft = MAXCMDTEXT - 4;
1345 	cmdtxt(n);
1346 	*cmdnextc = '\0';
1347 	return name;
1348 }
1349 
1350 
1351 static void
cmdtxtdogroup(union node * n)1352 cmdtxtdogroup(union node *n)
1353 {
1354 	cmdputs("; do ");
1355 	cmdtxt(n);
1356 	cmdputs("; done");
1357 }
1358 
1359 
1360 static void
cmdtxtredir(union node * n,const char * op,int deffd)1361 cmdtxtredir(union node *n, const char *op, int deffd)
1362 {
1363 	char s[2];
1364 
1365 	if (n->nfile.fd != deffd) {
1366 		s[0] = n->nfile.fd + '0';
1367 		s[1] = '\0';
1368 		cmdputs(s);
1369 	}
1370 	cmdputs(op);
1371 	if (n->type == NTOFD || n->type == NFROMFD) {
1372 		if (n->ndup.dupfd >= 0)
1373 			s[0] = n->ndup.dupfd + '0';
1374 		else
1375 			s[0] = '-';
1376 		s[1] = '\0';
1377 		cmdputs(s);
1378 	} else {
1379 		cmdtxt(n->nfile.fname);
1380 	}
1381 }
1382 
1383 
1384 static void
cmdtxt(union node * n)1385 cmdtxt(union node *n)
1386 {
1387 	union node *np;
1388 	struct nodelist *lp;
1389 
1390 	if (n == NULL)
1391 		return;
1392 	switch (n->type) {
1393 	case NSEMI:
1394 		cmdtxt(n->nbinary.ch1);
1395 		cmdputs("; ");
1396 		cmdtxt(n->nbinary.ch2);
1397 		break;
1398 	case NAND:
1399 		cmdtxt(n->nbinary.ch1);
1400 		cmdputs(" && ");
1401 		cmdtxt(n->nbinary.ch2);
1402 		break;
1403 	case NOR:
1404 		cmdtxt(n->nbinary.ch1);
1405 		cmdputs(" || ");
1406 		cmdtxt(n->nbinary.ch2);
1407 		break;
1408 	case NPIPE:
1409 		for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
1410 			cmdtxt(lp->n);
1411 			if (lp->next)
1412 				cmdputs(" | ");
1413 		}
1414 		break;
1415 	case NSUBSHELL:
1416 		cmdputs("(");
1417 		cmdtxt(n->nredir.n);
1418 		cmdputs(")");
1419 		break;
1420 	case NREDIR:
1421 	case NBACKGND:
1422 		cmdtxt(n->nredir.n);
1423 		break;
1424 	case NIF:
1425 		cmdputs("if ");
1426 		cmdtxt(n->nif.test);
1427 		cmdputs("; then ");
1428 		cmdtxt(n->nif.ifpart);
1429 		cmdputs("...");
1430 		break;
1431 	case NWHILE:
1432 		cmdputs("while ");
1433 		cmdtxt(n->nbinary.ch1);
1434 		cmdtxtdogroup(n->nbinary.ch2);
1435 		break;
1436 	case NUNTIL:
1437 		cmdputs("until ");
1438 		cmdtxt(n->nbinary.ch1);
1439 		cmdtxtdogroup(n->nbinary.ch2);
1440 		break;
1441 	case NFOR:
1442 		cmdputs("for ");
1443 		cmdputs(n->nfor.var);
1444 		cmdputs(" in ...");
1445 		break;
1446 	case NCASE:
1447 		cmdputs("case ");
1448 		cmdputs(n->ncase.expr->narg.text);
1449 		cmdputs(" in ...");
1450 		break;
1451 	case NDEFUN:
1452 		cmdputs(n->narg.text);
1453 		cmdputs("() ...");
1454 		break;
1455 	case NNOT:
1456 		cmdputs("! ");
1457 		cmdtxt(n->nnot.com);
1458 		break;
1459 	case NCMD:
1460 		for (np = n->ncmd.args ; np ; np = np->narg.next) {
1461 			cmdtxt(np);
1462 			if (np->narg.next)
1463 				cmdputs(" ");
1464 		}
1465 		for (np = n->ncmd.redirect ; np ; np = np->nfile.next) {
1466 			cmdputs(" ");
1467 			cmdtxt(np);
1468 		}
1469 		break;
1470 	case NARG:
1471 		cmdputs(n->narg.text);
1472 		break;
1473 	case NTO:
1474 		cmdtxtredir(n, ">", 1);
1475 		break;
1476 	case NAPPEND:
1477 		cmdtxtredir(n, ">>", 1);
1478 		break;
1479 	case NTOFD:
1480 		cmdtxtredir(n, ">&", 1);
1481 		break;
1482 	case NCLOBBER:
1483 		cmdtxtredir(n, ">|", 1);
1484 		break;
1485 	case NFROM:
1486 		cmdtxtredir(n, "<", 0);
1487 		break;
1488 	case NFROMTO:
1489 		cmdtxtredir(n, "<>", 0);
1490 		break;
1491 	case NFROMFD:
1492 		cmdtxtredir(n, "<&", 0);
1493 		break;
1494 	case NHERE:
1495 	case NXHERE:
1496 		cmdputs("<<...");
1497 		break;
1498 	default:
1499 		cmdputs("???");
1500 		break;
1501 	}
1502 }
1503 
1504 
1505 
1506 static void
cmdputs(const char * s)1507 cmdputs(const char *s)
1508 {
1509 	const char *p;
1510 	char *q;
1511 	char c;
1512 	int subtype = 0;
1513 
1514 	if (cmdnleft <= 0)
1515 		return;
1516 	p = s;
1517 	q = cmdnextc;
1518 	while ((c = *p++) != '\0') {
1519 		if (c == CTLESC)
1520 			*q++ = *p++;
1521 		else if (c == CTLVAR) {
1522 			*q++ = '$';
1523 			if (--cmdnleft > 0)
1524 				*q++ = '{';
1525 			subtype = *p++;
1526 			if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0)
1527 				*q++ = '#';
1528 		} else if (c == '=' && subtype != 0) {
1529 			*q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL];
1530 			if (*q)
1531 				q++;
1532 			else
1533 				cmdnleft++;
1534 			if (((subtype & VSTYPE) == VSTRIMLEFTMAX ||
1535 			    (subtype & VSTYPE) == VSTRIMRIGHTMAX) &&
1536 			    --cmdnleft > 0)
1537 				*q = q[-1], q++;
1538 			subtype = 0;
1539 		} else if (c == CTLENDVAR) {
1540 			*q++ = '}';
1541 		} else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) {
1542 			cmdnleft -= 5;
1543 			if (cmdnleft > 0) {
1544 				*q++ = '$';
1545 				*q++ = '(';
1546 				*q++ = '.';
1547 				*q++ = '.';
1548 				*q++ = '.';
1549 				*q++ = ')';
1550 			}
1551 		} else if (c == CTLARI) {
1552 			cmdnleft -= 2;
1553 			if (cmdnleft > 0) {
1554 				*q++ = '$';
1555 				*q++ = '(';
1556 				*q++ = '(';
1557 			}
1558 			p++;
1559 		} else if (c == CTLENDARI) {
1560 			if (--cmdnleft > 0) {
1561 				*q++ = ')';
1562 				*q++ = ')';
1563 			}
1564 		} else if (c == CTLQUOTEMARK || c == CTLQUOTEEND)
1565 			cmdnleft++; /* ignore */
1566 		else
1567 			*q++ = c;
1568 		if (--cmdnleft <= 0) {
1569 			*q++ = '.';
1570 			*q++ = '.';
1571 			*q++ = '.';
1572 			break;
1573 		}
1574 	}
1575 	cmdnextc = q;
1576 }
1577